Logical operators in Swift - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of combined logical operators

What is the output of this Swift code snippet?

Swift

let a = true
let b = false
let c = true
print(a && b || c)

A true

B false

C nil

D Compilation error

💡 Hint

Remember that && has higher precedence than || in Swift.

The expression a && b || c is evaluated as (a && b) || c. Since a && b is false, the result depends on c, which is true. So the final result is true.

❓ Predict Output

intermediate

Result of negation and OR operator

What does this Swift code print?

Swift

let x = false
let y = true
print(!x || y)

A nil

B true

C false

D Runtime error

💡 Hint

Negation (!) flips the boolean value.

!x is true because x is false. Then true || y is true. So the print outputs true.

❓ Predict Output

advanced

Output of complex logical expression

What is the output of this Swift code?

Swift

let p = false
let q = true
let r = false
print((p || q) && !r)

A Compilation error

B nil

C true

D false

💡 Hint

Evaluate inside parentheses first, then apply negation and AND.

p || q is true because q is true. !r is true because r is false. So true && true is true.

❓ Predict Output

advanced

Value of variable after logical operations

What is the value of variable result after running this Swift code?

Swift

let a = true
let b = false
let c = true
let result = !(a && b) && (b || c)
print(result)

A true

B nil

C Compilation error

D false

💡 Hint

Break down the expression step by step.

a && b is false. Negation !(false) is true. b || c is true. So true && true is true.

❓ Predict Output

expert

Output of chained logical operators with precedence

What does this Swift code print?

Swift

let x = false
let y = true
let z = false
print(x || y && !z || false)

A nil

B false

C Compilation error

D true

💡 Hint

Remember that && has higher precedence than ||, and negation applies before &&.

Evaluate !z first: true. Then y && true is true. So expression is x || true || false, which is true.